磷钨酸掺杂聚苯胺催化合成柠檬酸三辛酯及动力学研究

Synthesis and kinetics of trioctyl citrate catalyzed by H_3PW_(12)O_(40)/PANI

以H3PW12O40/聚苯胺（PANI）为催化剂,柠檬酸和异辛醇为原料合成柠檬酸三辛酯。考察了n（异辛醇）∶n（柠檬酸）、催化剂用量、反应时间等因素对反应转化率的影响,以及催化剂的重复使用性能,并测定了动力学数据。确定了较佳反应条件为n（异辛醇）∶n（柠檬酸）=5∶1、m（H3PW（12）O（40）/PANI）∶m（醇酸）=4%、反应温度≤140℃、反应时间4h。较佳反应条件下柠檬酸的转化率为96.6%;催化剂重复使用4次,柠檬酸的转化率为64.1%,反应总级数为二级,表观活化能为39.42kJ/mol,指前因子为1.972×10~2 L/（mol·min）。

Synthesis of trioctyl citrate from citric acid and iso-octanol on H3PW（12）O（40）/PANI catalyst was studied.Effects of reaction conditions,such as mole ratio of iso-octanol to citric acid,catalyst content and reaction time as well as the reusability of the catalyst were investigated.The kinetic data of this system were measured in a batch reactor.The optimum reaction conditions were obtained：n（iso-octanol）∶n（citric acid）=5∶1,m（H3PW12O40/PANI）∶m（citric acid and iso-octanol）=4%,reaction temperature≤140℃,reaction time4 h.The results showed that conversion of citric acid can reach 96.6%;and activity of catalyst is still kept at64.1%after being used 4times,the synthesis of crioctyl citrate is a second-order reaction on H3PW（12）O（40）/PANI catalyst,the apparent activation energy of 39.42kJ/mol,the pre-exponential factor of 1.972×102L/（mol·min）for H3PW（12）O（40）/PANI catalyst was obtained.